Project Summary Scholarly and public interest in fatherhood has increased in recent decades, and this interest has coincided with revised cultural perceptions about what makes a good father. In addition to serving as breadwinners and protectors, fathers are also expected to be engaged in their children's lives. These competing demands contribute to work-family conflict, yet scholars have largely ignored one important work-family policy: paternity leave. Paternity leave can provide fathers with opportunities to learn parenting skills, bond with their child, and strengthen father identities while also maintaining employment. Thus, paternity leave can enable fathers to adhere to the expectations of both traditional and new fatherhood by encouraging fathers to contribute resources that facilitate child development. Paternity leave-taking may also alleviate mother's stress and work- family conflict by offering families a respite that may lead to increases in co-parents' relationship quality and mother's well-being. As a result, increased access to paternity leave may help to reduce gender inequality by allowing mothers to (re)enter the labor force sooner if they so desire, improving mothers' earnings, and reducing mothers' share of domestic tasks. Unfortunately, little is known about why fathers do (or do not) take paternity leave and what influence paternity leave-taking may have on families. Using longitudinal data from three national datasets (the National Longitudinal Study of Youth 1997, the Early Childhood Longitudinal Study-Birth Cohort, and the Fragile Families and Child Wellbeing Study), the proposed study examines the relationship between paternity leave and family well-being by focusing on who takes paternity leave, and whether and how paternity leave is associated with indicators of short- and long-term family well-being. We address three specific aims in this study: (1) specify patterns of paid and unpaid paternity leave and identify predictors of the likelihood of taking paternity leave and the length of leave taken, for both paid and unpaid leave, (2) examine whether and how paternity leave-taking is associated with father involvement, co-parents' relationship quality, and mother's feelings of well-being, and (3) analyze the relationship between paternity leave-taking and children's well-being, and the extent to which father involvement, co-parents' relationship quality, and mother's feelings of well-being mediate this relationship. We examine the patterns and consequences of whether fathers take paternity leave as well as length of paternity leave. Indicators of child well-being include overall health, problem behavior, and cognitive ability. We employ a variety of statistical techniques including regression modeling, propensity score matching, and multilevel models. Overall, a focus on the patterns, predictors, and consequences of paternity leave-taking will provide insights into the potential of paternity leave policies to reduce work-family conflict and promote family well-being. Such insight will inform scholars and policymakers about the implications of the current structure of paternity leave in the U.S., and whether an expansion of these policies may be beneficial to families.